Furnace



June 20, 1933. G. NAISMITH El AL 1,914,956

' FURNACE Filed May 26, 1931 6 Sheets-Sheet 1 (fiVEjVTORS BY .I'TORNEY June 20, 1933. NAlsMlTH ET AL 1,914,956

FURNACE Filed May 26, 1931 6 Sheets-Sheet 2 4/, a-.' Gas Prod/Jai s of Combusiion Hu/eE Z June 20, 1933. 5. NAlSMlTH ET Al.

FURNACE 6 Sheets-Sheet 3 Filed May 26, 1931 F/ urea-3 A TTORNEY June 20, 1933.

G. NAISMITH ET AL FURNACE Filed May 26, 1951 6 Sheets-Sheet 4 QQQMBQEQ \o hmubxvokm ILYIF MI. xx

MVW ll! km ll! W mw u b I m. M NN W June 20, 1933. G. NAISMITH ET AL 1,914,956

FURNACE Filed May 26, 1951 e Sheets-Sheet s w W I b INVENTORS L: 5mm

A TTORNEY June 20, 1933. NNSMITH ET A 1,914,956

FURNACE Filed May 26, 1951 6 Sheets-Sheet 6 21 4 t V A TTORNEY I opposite end.

- Patented June 3 ,UNITED .srATssj' PATENT. orrlcs GEORGE NAISKI'IE AND DONALD H. NAISHITH, 0F PI' E'I SBUBGH, PENNSYLVANIA,

' ASSIGNOBS T0 DONALD E. NAISMITH, 0F PITTSBURGH, PENNSYLVANIA FURNACE Our invention is an improvement in heating furnaces of the regenerative type particularly adapted to the heating of ingots and the like within a soaking pit; or heating chamber.

- It has in view to provide a furnace construction in which the gases of combustion are supplied to one side ofthe soaking pit and withdrawn from the other, with circula tion throu h the pit from side to\side either in a horses oe travel, as to all or some of the gases, or directly across from one end to the In our improved construction we providemeans for preheating the air and gas in their assage through a. regenerative chamber emodying gas circulating channels or-ports, with combination of the pre-heated air and gas in a common mixing chamber leading to one side of the soaking pit; a similar corresponding construction leading from the other side of the soaking pit for the outgoing gases or products of-combustion; fuel supply means supplementing such gas supply, either through the checkerwork of the regenera tive chamber, or thereabove at the remote end of the mixing chamber, or both; means controlling supply of producer or like gas to the pre-heating ports extending through the regenerative chamber, means controlling supply of air thereto; means controlling withdrawal of the waste gases; and various other features of construction and advantage, as hereinafter described and claimed.-

/ The present improvement and construc- I tion is particularly adapted to the pre-heating of the fuel supply by incorporating the v circulating flues therefor with the regenerative chamber and in close association with the checkerwork thereof, thereby subjecting the flues themselves in such checkerwork to the heating actionof outgoing ases with the resulting advantage of preeating upon.reversal of the circulation for both the air and 45 gas, with the resulting advantages of inn roved and accelerated combustion upon comhination of both immediately upon entering the mixing chamber.

Byour improved construction we are en 'abled to simplify the reversing "valve and a side. of an intervenin 1931. Serial No. 5403M.

damper installation to reverse the gas ci r culation from its entrance to the soaking pit and outlet therefrom in combination with the gas ports passin through the air regenerator,

with correspon ing reversal of circulation in' through the furnace on the line l[ l of Fig. 2,

showing the gas supply fines incorporated with the regenerator and in outgoing circulation with the stack; Y

Fig. 2 is a horizontal section, part plan view, on the section line H-H of Fig. 1,

showing the air and gas pie-heating regenerative chambers in operative relation toone side and the other of a double hole soakingpit;

Fig. 3 is a vertical-sectional view on the hue lll1l of Fig; 2, showing the circulation of incoming air and outgoing waste gases delivered to and withdrawn from each side of the furnace respectively;

'Fig. 4 is a transverse vertical section on the line IVIV of Fig. 2;

Fig. 5 is a similarsection on the line VV of Fig. 2;

Fi 6 is a similar section on' the line VI- I of Fig. 2;

. Fig. 7 is a butshowing t tion; c o

, Fig. 8 is a partial similar section on the line VIIIVIII of Fig. 2;

art sectionalview like 1 e gas flues in supply circula- Fig. 9 is a horizontal sectional view simi- 7 pit of acontinuouslytrated two arrangements of air andgas pre heating regenerative chambers, in one of which such chambers are arranged side by partition wall, one leading to one side of e soaking pit and the of the furnace is pre v main holes or cavities 2a and 2b of generally Referring to the principal figures of the.

drawings, the soaking pit or heating chamber erably divided into two rectangular construction enclosed within side walls 33, outer end wall 4, and an inner transverse partition 5. The latter forms a partial closure of the heating chamber, pro-.

' viding the end wall of the regenerative portions of the furnace which are also enclosed between the main side walls 3 and the opposite end wall 6.

A central partition wall 7 extends vertically from the base of the construction upwardly to the roof forming a support for the arched roof coverings 88 of the regenerative chambers containing the checkerwork 9, and the common mixing and combustion chamber 13. Such roof arches extend longitudinally from partition to end wall 6. As shown, wall 7 extends by partition wall 10 across and through the middle of the two-hole soaking pit, having an arched communicating opening 11 for circulation of heating gases therethrough from one hole 2a to the other hole 2b.

The two-hole soaking pit, as thus constructed, is of ample depth for the placement of ingots of normal height, resting on the supported floor 14 carried by beams 15 or otherwise and provided with the removable cover or covers 16 mounted by wheels 17 on suitable tracks or runways, following general practice.

In our improved construction we preferably utilize producer gas or other equally efiicient fuel leading from a conduit or tunnel 18 through circulating flues 19 leading to transverse supply passages 20 arranged vertically below and communicating with a series .of vertical ports 21. Such ports are arranged transversely across the width of each regenerative chamber, alternating and in close as-' sociation with the checkerwork thereof, as in Figs. 2 and 6, and opening into mixing chamber 13.

The main body of checkerwork 9 extends from the outer side of such gas circulating ports 21 backwardly for the full depth of the gas ports and of the chamber beyond, and of its full width, beyond the ports 21.

Below the checkerwork extends a series of circulating flues 22, communicating with the main body of the checkerwork and its extensions between ports 21. Flues 22 are divided by comparatively thin supporting walls underneath the checkerwork, beyond which is a widened common communicating due 23, the

is at each side of the blower or fan B and has a pipe 25which communicates laterally with the wind box and fan B and leads upwardly within the base of outlet stack 26.

Intervening between main 18 and ports 21 of circulating main channel 19 is a cut-off damper 27 of well known commercial type, by the operation of which the gas supply to one or the other side of the heating chamber is furnished. A cross port 28 opens and closes communication between fines 19 and 23 by control of an opening and closing damper 29.

By closing damper 29 gas supply is directed to ports 21 and by opening the damper, reverse circulation is opened-to flue 23 and stack 26. The latter is connected by its operating stem 30 with lever mechanism 31 for operation of an opening and clos ng valve 32,

adapted to cooperate with damper 29.

Such damper and valveare capable of bein adjusted to each other, as to relative circu ation clearance, so as to regulate the draft through flues 19 and 22-23 during operation. This is of importance in case checkerwork is also placed in flue 19 and ports 20 and 21, or any of them, for additional regeneration.

Supplemental fuel supply, as by blast furnace gas, is introduced by pipe or pipes 33 leading through wall 6 to the end portion of mixing chamber 13, or by pipe or pipes 34 to the chamber 35, within the body of the checkerwork. By such arrangement comparatively lean gas, such as blast furnace gas, is admitted to those portions of the installation where it will be immediately combined with highly heated air, as with the pre-heated air passing through and above the checkerjacent hole of the soaking pit.

The gases of combustion pass from the other side or hole of the pit, circulating downwardly through the main body of checkerwork 9 and also through the ports 21, such latter circulation passing through open port 28 and combining with the main current of waste gases from the checkerwork and outwardly through stack 26.

It will be understood that two such stacks are provided, one at each side as shown in Fig. 2 for alternating operation for intake of 15 Likewise, with damper 29 and vnlve 32 closed, air from the wind rm 2 lwill he re-= versed downw dly and passes by ports 23, upwardly rough the checlrerssnd com blues with preheated gas in the milling chamber 13. he circulation is reversed at vals from time to time, with or without "l g supplemental supply oi: p s 33 or 3 1 or both. 7

e soelzing pit 2 is located oppositely extending gore-heating 1y chambers, as rnace well known construcendrnost chemloers, eec ir fuel and supply, as shown igs, end such case the longitudinal. cavity is enclosed wi hin side walls 3, 3, and ends wells 6, 6. The lower gas ports 19 communicate an outer i8 and the upper sir ports 23 lead from as separate blower end sir lion combined with single outlet stools so us shown, one at each outer end of the furnsce, operating alternately for each reversnl,

The construction and operation is otherthe some as alcove described, the circuls tion of air gas in combustion pwsing directly across and through the soaking pit 2 end then downwardly through the gas ports and checker 9 to the stack, when damper 29 is raised,

in each case the fuel gases psss into one side or the soaking pit and out the other side, with pro-heating oi the gas fiues 2i embodied inthe surrounding checkers of the regenerative chamber. Likewise'additional fuel may be supplied to the remote end of the mixing chamber "by pipes 33 and 3%, as desired.

The construction and operation oithe ifurnace will be readily understood from the foregoing description. llt provides for a highly eiiicient and economical application and use of the fuel in its application, withimaximum conservation and values.

lVhat we claim is v i. In a furnace, the combination with a. soaking pit, of walls enclosing a chamber leading into one side of the soaking pit and a correspondingwh-amber. leading from the other side thereof, a regenerator for each of utilization of waste heat said chambers, means supplying air to one of said regeneratcrs, enclosed fuel conducting ports leading upwardly through and between opposite portions of said regenerator' for admixture with heated air at the top thereof, and means controlling supplyoif air and fuel to one regenerator and withdrswel of waste gases from the other.

2. lln a furnace provided with atwo-hole soaking pit, the combination therewitlioi' walls enclosing o chamber leading into one hole and s corresponding chuinher leading into the other hole, means einloodying sir. heuting checircrworls and a series oi closed. gas heating iiues extending bodily through the checlrerworlr for supplying fuel through. said chamber to one of suid holes, and menus embodying siniiler checkerworlr end for exhausting wast gases through said chamber from the other 3. In :furnece provided wrtn o soaking pit, the combination wells enclosing chamber leeoi hole and at corresponding chemo into the other means entice heetingcheclrerworlr uncle series of c ilues extending bodily checlrerworlr for supplying through said chamber to one of means embodying similar fines exhausting waste gases said chamber from the other hole, "for supplying additional fuel the cliuinter shove the checlrerworlr.

i. In a furnace provided with lJWiD lllOlE v soaking pit, the combination therewith of wells enclosing chamber lending into one hole and s corresponding chamber leading into the other hole, means ernhodyiuig sir heating checlrerworlr and u series of closed gas heating dues extendingloodily through the checkerworlr for supplying heating fuel, through said chamber toone of said holes, means embodying similar checkerworlr end dues for exhausting waste gases through snid chamber from the other hole, and means tor supplying additional fuel to the checizerworh forccirculation therethrough to ssid chomlier.

5. lln u furnace, the oornloinstionv with u soaking pit, of walls enclosing a chamber leading into one side of the soaking pit and a corresonding chamber leading from the other si thereof, a regenerator for each of said chambers, a conduit supplying air and a conduit supplying gas at times to each one of said regenerators, said conduits having a communicating port therehetween, an outlet lIU steel: in communication with the air conduit having an opening and closing valve,

and a damper for the communicating port cooperating and connected with the valve adapted to control circulation of outgoing gases at other times to the stack.

6. In a furnace, the combination with a 130 a both conduits and through said port to the stack, and means supplying air through the base of each stack for inward circulation through the air conduit and checkerwork of each of said chambers.

7. In a furnace, the combination witha soaking pit, of walls enclosing a chamber leading into one side of the soaking pit and a corresponding chamber leading from the other side thereof, a regenerator foreach of said chambers, means including a flue sup-,

plying air at times to one of said regenera tors, an outlet stack in communication therewith having an opening and closing valve, a fuel supply conduit, and a damper-controlled opening between the air supply flue and the fuel supply conduit adapted to *provide cir culation o outgoing gases from said flue and conduit at other times to the stack.

8.- In a furnace, the combination with a soaking pit, of walls enclosing a chamber leading intoone side of the soaking pit and a corresponding chamber leading from the other'side thereof, a regenerator for each of said chambers, an air supply conduit and a separate adjacent fuel supply conduit directin th ough and between opposite portions of one regenerator respectively and a similar 'pair of conduits for the other regenerator,

said pairs of conduits operating alternately for reverse outward circulation, a single outlet stack for each pair of conduits, and a damper controlled port. connecting each pair of conduits adapting them to'operate independently, for air and fuel supply or together for exhaust to the stack.

9. In a furnace, the combination with a soaking pit, of walls enclosing a chamber leading into one side of the soaking pit and a corresponding chamber leading from the other side thereof, a regenerator for each of said chambers, an air supply conduit and a separate adjacent and parallel fuel supply,

conduit directing air and fuel respectively upwardly through and between opposite portions of one regenerator respectively and a similar pair of conduits for the other regenerator. said pairs of conduits operating alternately for reverse outward circ'ulation, a single outletstack for each pair, of conduits provided with an opening and closing valve, a port connecting each pair of conduits, and

air and fuel respectively upwardly a damper therefor operatively connected with the stack valve.

10. A reversible heating furnace having a heating chamber and a single regenerative chamber provided with an upper mixing and combustion cavity opening into the heating chamber and independent air and gas supply passages both extending bodily through and within' the lateral area of the regenerative chamber for pre-heating and mixing and combustion in the upper cavity.

-'11. A reversible heating furnace having a heating chamber and a single regenerative chamber provided with an upper mixing arid combustion cavity opening into the heating chamber and independent air; and gas supply passages both extending bodily through the regenerative chamber for pre-heating and mixing and combustion in the upper cavity, and circulatlon and control means including a damper-controlled communicating port be tween the air and gas supply passages whereby the regenerator on reversal serves as an outlet conductor for waste gases. I

p 12. A furnace having a pair of main endmost heating chambers, a middle vertical wall with a circulation opening in its outer portion connecting the heating chambers, outer vertical end walls for the heating chambers, a

lower air pro-heating chamber at each opposite sideof said middle wall, a side-by-side pair of common mixing, combustion and delivery conduits each communicating with one of said pre-heating chambers and with one of the main heating chambers at each side of said middle wall, said conduits extending continuously from the main heating chambers to opposite inner end walls of the pre-heating chambers, means for supplying an upwardcirculation of air through the pre-heating chamber at one side of the middle wall and for exhaust circulation through and from the ieatingchamber at the other side of said wall, and means for introducing fuel through the inner end wall of each common mixing, combustion and delivery conduit above the air pre-heating chamber.

-. 13. -A furnace having a pair of main endmost heating chambers, a middle vertical wall with a circulation opening in its outer portion connecting the heating chambers, outer vertical end walls for the heating chambers, a lower air 'pre-heating chamber at each opposite side of said middle wall, a'

side-'by-side pair of common mixing, combustion and delivery conduits'each commu- 1 nicating with one of said pre-heating charm hers and with one of the main heating chambers at each side of said middle wall, said conduits extending continyously from the main heating chambers to opposite inner end walls of the pre-heating chambers, means for supplying an upward circulation of air through thepre-heatin chamber at one side of the middle wall an for'exhaust circula- Vheeting chamber, all of said pro-hosting hers, seid conduits being prcvid trolling vnlves'ior clternnting the circulc communicating with thelower portions of the ore-hosting chambers and heving con-1 chambers, common delivery conduits and supply pipes being erred on opposite sides of the middlevertic'el Well, the delivery conduits communicating with the main heetin chambers at each side thereof.

i i l iiurnuce heving main Wells enclosing s pair of meinendmosttrnnsversely co nmuniceting heatingchembers, lower sir preheating chambers separated by a common wall and respectively communicating with the inner portions oi thehenting, chembcrs opposite sides thereoi for incoming end,

outgoing circulation on e common horizontal plane, and having continuous incoming outgoing conduits communicating vertically with all portions oil the pro-ho l ng chemwith contion throughsoid pro-heating chambers incoming and outgoing circul through, and means for introduc into the snid conduits and into \i: tion of pro-heated sir at points remote W 0-. the heating chambers,

l5, A "furnace heving main outer enclosing e poir of endmost chemhers at each side of e middle division Well having it circulation opening therethrough, said division wall having on opposite sides thereof it of lower parallel. sir pro-hecting chambers ouch communicating by u continuousconduit with the inner portion of that heating chamber upon the corresponding side of said division woll'ior incoming and outgoing horisontsl circulation through the heating chambers, snidconduits extend-l ing above the entire ares of the pro-hosting chambers, conduits serving alternatively for air supply and fuel exhaust respectively trolling valves for reversing the circulation, and moons for introducing fuel into each conduit at a point remote from the main hosting chember.

16. ln s furnace having main Wells enclos in endmost main heatin chambersse srated by a middle transversely open dividing Wall, and side-by-side lower vertically circulating sir preheating checkerw'orl:

chambers in duplicate arrangement, said middle vertical wall having on opposite sides thereof upwardly extending mixing chambers communicating respectively with said checkerwork chambers, mixing charm bers between the main heating chambers and each of said checkerwork chambers extending shove the checkerwork chombers approxsaid chambers, means for introducing an independent suaply of fuel to each of said mixing chem ers above the checkerwork chambers at a point remote from the main heating chambers, and means for alternately supplying air to one of said checkerworh chambers and Withdrawing Waste gases from theother,

1'7 A. furnace es in claim 16 having the mentioned fuel introducing means in the and also characterized by the inclusion vvi the lower portion of each checker-Work chamber of means lor introducing fuel gas thereinto for upward circulation through the checlrervvorlr chamber into the mixing chem- 1 A furnace es in claim 16 having the mentioned fuel introducing means in the form oi gas supply above the checkervvorlr and remote from the main heating chamber colso characterised by the inclusion Within the lovrer portion of each checlrervvorlr chain V her of enclosed supplen en'tnl chamber in its flow towards the mixing chamber, said chamber being of the full length and extend- .imately half the depth and full length of form of or gas supply above the checkervvorh I and remote from the mmnhestmg chempers hin ing beyond the air pre-heeting menus to the soelring pit, means controlling air supply to the sir pro-heating means, and a mixing" chamber leading from the opposite soaking pithoving similar fuel supply means one lower sir pro-hosting means adapted to also provide for outgoing circulation of WESbS gases V 26 In combination, n pair of side-by-side mesnsior admitting a combustible mixture into one pit thereof consisting of e longitudinal mixing chamber, means for supplying fuel gas to the outer end of the mixing chamber, means below the mixing chamber and gas supply therefor for pro-heating air in its flow towards the mixingchamber, said chamber being of the full length and extending beyond the air pro-heating means to the soaking pit, means controlling air supply to the sir pro-heating means, 5 mixing chamber leading from the opposlte soak ng pit having similar fuel supply means and lower air pro-heating means adapted to also provide for outgoing circulation of waste gases,

transversely communicating soaking. pits, 116

mixing chamber being of the full length and extending beyond the air pre-heating chamber to one of the main heating chambers, air circulating checkerwork in the'pre-heating chamber, a fuel supply at the outer end of the mixing chamber, a return circulation chamber like the mixing chamber leading oif from the opposite main heatingchamber and having a similar fuel supply, a waste gas chamber like the air pre-heating chamber communicating with the mixing chamber and with a waste gas outlet, gas circulating checkerwork like the air circulating checkerwork in the waste-gas chamber, means controlling infiow of air to the air pre-heating chamber, and means controlling outflow of waste gases from the waste gas chamber.

22. A furnace as in claim 21 characterized by means supplying gas for upwardflow through the checkerwork for combination with air in the mixing chamber.

23. In a furnace, the combination with plural soaking pits, of enclosing side and end walls and a longitudinal division wall with a transverse opening located inwardly from the .outer end walls and extending from the having regenerative checkerwork therein and an upper mixing portion communicating with the corresponding heating chamber, means for alternately supplying air to one of said chambers while withdrawing waste gases from the other; and means for introducing fuel gas to the lower portion of each chamber for upward circulation through the checkerwork-therein. "26. In a furnace, main outer walls enclosing two main transversely communicating heating chambers and corresponding lower vertically circulating air chambers having regenerative c eckerwork therein and an upper mixingportion communicating with the corresponding heating chamber, means for alternately supglyingair to one of said chambers while w1 drawing waste gases from the other; an enclosed supplemental chamber in-the lower portion of each checkerwork chamber communicating downwardly with the air supply and upwardly through the checkerwor and a fuel supply pipe leading into said supplemental chamber.

In testimony whereof we hereunto afiix our signatures.

GEORGE NAISMITH.

' DONALD M. NAISMITH.

end walls between the soaking pits and rear- I wardly therefrom providing an uppermost chamber leading into one soaking pit and an uppermost chamber'leading from the other soaking pit at the opposite side of said dlvision wall, means sup lying fuel through the inner end walls to eac of said uppermost chambers, a regenerator below each of said chambers, means supplying both fuel and air to each of said regenerators, and means controlling supply of air to one regenerator and withdrawal of waste gases from the other, whereby the flame travel through the soaking pits is alternatively reversed at intervals.

' 24. A reversible regenerative heating furnace having a pair of regenerators and two ma n soaking pit chambers separated by a dlviding wall having an opening therethrough, air and gas passages leadingthereto and therefrom through the regenerators; and

circulation control means for' said passages whereby both air and gas are pre-heated in i a single regenerator and whereby said regenerator on reversal serves as an outlet conductor for waste gases. I

25. In a furnace, main outer walls enclosing two main transversely communicating heating chambers and corresponding lower vert' cally circulating air pre-heating chambers re-heating 

